Phonograph and analogous apparatus



E. GRISSINGER.

PHONOGRAPH AND ANALOGOUS APPARATUS.

APPLICATION FILED JUNE 12, 1918.

1,339,558, Patented May 11,1920.

INVENT9R 1% 1 1 M 6M 1 a ATTORNEY UNITED STATES PATENT onnron,

ELWOOD GRISSINGER, OF BUFFALO, NEW YORK, ASSIGNOR TO LUCY ASHGRISSINGER, OF BUFFALO, NEW YORK.

PHONOGRAPH AND ANALOGOUS APPARATUS.

Application filed June 12,

To all whom it may concern:

Be it known that I, ELWOOD GRIssINonK, a citizen of the United States,and resident of Buffalo, in the county of Erie and State of New York,have invented certain new and useful Improvements in Phonograph andAnalogous Apparatus, of which the following is a specification.

My present invention is shown as embodied in a phonographic sound boxwhich is primarily adapted for mechanically reproducing sound from arecord but it may be embodied in a phonographic recorder or otherapparatus where rigid, frictionless, noiseless pivoting is necessary ordesirable in order to insure faithful, undistorted mechanical receivingor transmission of high frequency or complex wave energy.

In In prior application, Serial No. 236,735,

ay 27th, 1918, I have disclosed a construction wherein the effects ofmechanical resonance are eliminated from the vibratory system, by makingthe lever arm rigid and pivoting it upon spaced piano steel wiresstretched to the safe limit of their tensile strength thereby insuring apredetermined, rigidly fixed path of movement for all parts or particlesof the lever.

My present invention may include the above features but it relates moreparticularly to the use of the spaced stretched wires and it involves inaddition thereto, a means for further predetermining and fixing thelocation of the pivotal axis of the lever. Broadly stated, the saidmeans consists of a third element adapted to apply a thrustperpendicularly to the plane of the wires, and along a line parallelwith and midway between them. The means employed for this purpose may bea knife edge or a cylinder of small diameter or a pair of alined steelballs.

By providingsuitable adjusting screws, the pivotal edge or surface maybe powerfully forced against the lever thus affording a convenient andvery effective means for transversely displacing the wires and therebystretching them to any desired degree of tension.

By the above expedient, the knife edge or alined balls become thephysical bearing surfaces for the pivotal movement of the lever. Thesebearing surfaces are forced into contact with relatively enormouspressure by the symmetrically applied stresses Specification of LettersPatent.

Patented May 11,1920.

1918. Serial N0. 239,512.

of spaced wires. This prevents all possibility of jumping or noiseproducing movements at the point of contact of the lever with itsbearing. The bearing parts are preferably of very hard steel and areformed with smooth, preferably polished surfaces.

My invention will be more fully understood from the following detaileddescription thereof in connection with the accompanying drawings, inwhich Figure 1 is a face view of a phonographic sound box showing thespaced stretched wire suspension;

Fig. 2 is a section on the line 22, Fig. 1, the lever and pivotalmounting being shown in side elevation;

Fig. 3 is an enlarged vertical section on the hne 3-3, Fig. 1;

Fig. 4, is an elevation endwise of the lever.

In these drawings, the sound box comprises the annular ring 1, formedwith the inwardly projecting annular flange 2, and the back-plate 3,secured to ring 1 by screws 4. In the recess between flange 2 and plate3 is clamped the diaphragm 5 of mica or other suitable material,disposed between a pair of rubber cushioning rings 6 which may be of anyknown or desired material or construction.

The annular ring 2 is formed on one side with an enlargement 7 adaptedto form a solid base support for the mounting of the stylus lever. Thebackplate 3, is shown as provided with an annular rubber collar 8carrrying an internal ring 9 provided with lugs 10 adapting it forbayonet connection with slots on a phonograph arm where the device isused for reproducing or a mouthpiece where the device is used forrecording.

The lever arm 11 may be attached to the diaphragm directly or throughthe screw and adjustable units shown in Fig. 2. The other end of thelever is provided with a socket 12 and binding screw 13 for holding aneedle for reproducin or a cutting point for recording, as in icated at14. This lever is preferably of an aluminum alloy, and the pivotalportion is relatively massive for purposes of strength, and because acertain amount of weight near the pivotal axis is not so objectionableand is in some respect advantageous so far as con cerns pure tonetransmission.

The resilient members adapted to permit resilient pivotal movements ofthe lever while powerfully opposing movements in other directions areshown as comprising 2 wires 15, 16, symmetrically arranged with respectto the pivotal axis and also with respect to the longitudinal axis ofthe lever. The wires are secured to the lever arm in any desired way, asfor instance, by thread ing them through passages 17, 18 (Fig. 2%.

These passages are preferably parallel. with each other and with thediaphragm.

The ends of the wires are secured to clamping posts 19, 20 by clampingplates 21, 22, each secured preferably by a central bolt 23, passingdownward between the wires so that the clamping plates will bind equallyon both of the wires to be secured thereby.

As shown in the drawings, the wires are comparatively close togetherwhere they pass through the lever and are spread apart to a considerablywider distance at their clamping points so that when highly tensioned,they have considerable effect in bracing or staying the lever againstlongi* tudinal movement and also against any skewing of its pivotalaxis.

Such spaced wires when very highly tensioned afford a frictionless,noiseless mounting for pivotal movement of the lever about an axisparallel with and midway between the Wires. According to my presentinvention, I use a physical means for determining the axis consisting ofa transverse member 24, having a thin or V or knife edge 25 appliedagamst the lower side of the lever at 26 so-as to have line contacttherewith in a plane midway between the spaced wires. The member 24: isshown in the form of a blade slidably mounted in the frame and adaptedto be thrust upward vertically against the lever as powerfully as may bedesired, by means of screws 27, 27.

The blade may be set with the bearing edge thereof at the desired heightwith reference to the clamping points of the wires by means of the setscrews or it may be permanently fixed in such position with the wiresstrung loosely through the lever and clamps. Then the wires may bestretched to the desired tension by any suitable tensioning appliances,after which the clamps may be screwed tight. The maximum tensioning withleast displacement of the wires and: least danger of breaking them, maybe obtained by the same method except that the bearing will first beretracted, and after stringing, highly tensioning and clamping the wiresin a single plane, the bearing screwed up to deflect the wires andthereby increase the tension to the desired extent. The adjustablebearing may be used as the sole tensioning appliance, the wires beingdrawn snug by hand in a single plane so as to get them practically equaland symmetrical, then clamped and bearing screwed up until the desiredtension is applied.

The bearing edge of member 2a need not he a 90 angle as indicated inFig. 3 but may be a 60 angle, or even sharper. The extreme edgeaffording the straight lline contact with the lever may be a sharpconvergence of the planes or may be slightly smooth or rounded, an edgecoresponding to a cylinder of say one-lmndredth of an inch, more orless, being in some respects the equivalent of and in other respectssuperior to the sharp edge angular convergence.

The spacing as well as the divergence of the wires may be varied withinwide limits, provided only, that they be spaced apart so as to affordspaced apart planes of opposition to the thrust of the bearing edge orsurface which takes effect in the plane between them in order to producethe desired condition of stable resilient stresses.

From one viewpoint, the preferred embodiment of my present invention maybe considered as involving the use of the highly tensioned wires whichare claimed broadly in my said prior application, Serial No. 236,735, incombination with a solid physical means for determining the pivotal axisand as a substitute for the noisy, imperfectly acting springs, etc.,which have been employed heretofore in phonographic apparatus, in thevain attempt to prevent jumping, rubhing and shifting of the pivotalbearing surfaces of the lever. The wires employed by me when stretchedto sufiiciently high tension, eleminate all noises due to the imperfector rubbing contact of the bearing surfaces and they introduce no noisesof their own because the free portions thereof are of such small massand of such high tension that any natural frequency vibrations which maybe set up in them are of very small total energy and are of too highfrequency and too musical in quality to be observable among the waveforms transmitted therethrough either in recording or re n'oducing.

Furthermore, my physical. bearing and stretched wire combination isremarkably effective in reducing and practically elimis nating needlenoises which are so often disagreeably prominent in reproduction ofsounds from ordinary records. There is some reason to believe that therelatively massive proportions of the part of the lever arm utilized forsustaining the thrust of the bearing and the stress of the stretchedwires, in combination with extreme light ness of the remainder of thelever arm contribute to some extent to eliminating of needle noises.

The instrument being substantially free from needle, bearing, spring andother disturbing noises, damping, which is commonly employed for thepurpose of reducing such noises, is unnecessary. The damping in mydevice is extremely small, and is limited mainly to internal molecularfriction which operates substantially equally for all frequencies. Thisavoids the unequal damping out of the higher frequencies and theresulting distortion which is inevitable where the damping is due tofriction.

Regardless, however, of explanations as to causes, it is a fact that aphonograph reproducer made in accordance with my present disclosure,faithfully produces, without needle noises and without any internallyoriginated noises or notes, all of the more delicate overtones traced inthe record not observably reproduced by any phonograph apparatus now onthe market and it does this in louder volume and without the needlenoises and without adding any internally generated noises or notes ofits own. This superiority holds even when the tension of the wires isdecreased very far below the safe limit of tensile strength. of thewire.

For the resilient tension members, I prefer to use wire approximatelylike No. 6 piano wire which is fine quality steel wire about .011 to.012 inch in diameter, but the material and size of the wire may bevaried within wide limits and I have at different times and with variousobjects in view used finer wires and also larger wires up to .02 andeven .034 inch in diameter. It is obvious also that tension membersother than wire may be employed and that the cross section need not becircular.

I claim:

1. I11 an apparatus of the class described, a lever, means for vibratingsaid lever, a suitable support, and means for pivotally mounting saidlever on said support, said means comprising bearings, one of which isformed with an edge bearing having pivotal contact with the surface ofthe other bearing on a line at right angles to the plane of the pivotalmovement, in combination with wires of great tensile strength secured tothe support and engaging said lever symmetrically with respect to thepivotal line and extending in directions adapted to stress said leveragainst said bearing, and adjustable means for stretching said wires toa tension approaching the limits, of safe elastic stress.

2. In an apparatus of the class described, a lever, means for vibratingsaid lever, a suitable support and bearings, one of which is a knife orV-edge bearing having pivotal contact with the lever on a line at rightangles to the plane of its pivotal movement, in combination with highlytensioned wires secured to the support and engaging said leversymmetrically with respect to the pivotal line and extending indirections adapted to stress the pivotal bearing surfaces into perfectnon-slip engagement.

3. In an apparatus of the class described, a lever, means for vibratingsaid lever, a suitable support and bearings, the latter having straightline elements in pivotal contact with the lever on a line at rightangles to the plane of its pivotal movement, in combination withlongitudinally lengthened piano wire secured to the support, engagingsaid lever adjacent said line of pivotal contact and extending indirections adapted to stress the pivotal bearing surfaces into perfectnon-slip engagement and means for stretching said wire to a tensionapproaching the limits of safe elastic stress.

4:. In an apparatus of the class described, a lever, means for vibratingsaid lever, a suitable support, a solid bearing having line contact withthe lever on a line at right angles to the plane of its pivotalmovement, in combination with highly tensioned wires secured to saidsupport and engaging said lever symmetrically with respect to the lineof pivotal contact and extending in directions adapted to stress saidlever against said bearing.

5. In an apparatus of the class described, a lever, means for vibratingsaid lever, a suitable support, a solid bearing having line contact withthe lever on a line at right angles to its plane of movement, incombination with highly tensioned wires secured to said support andengaging said lever adjacent said line of pivotal contact and extendingin directions adapted to stress said lever directly downward againstsaid bearing and to aiford balanced lateral stresses adapted to preventskewing of the lever upon the bearing.

6. A sound box having a diaphragm, a lever secured to the diaphragm,bearings on the box and on the lever having line con tact with eachother on a line parallel with the diaphragm and at right angles to thelever, in combination with wires secured to the sound box and engagingthe lever from different directions such as will afford tension stressescooperating to press the lever bearing downward upon the box bearing,but mutually opposed and approximately balanced in other directions, andadjustable means for moving said bearings and lever substantiallyagainst the downward pressure to increase the longitudinal tension ofthe wires and the amount of said downward pressure without substantiallydisturbing the approximate balance of their tensions in otherdirections.

7. A sound box having a diaphragm, a lever secured to the diaphragm,bearings on the box and on the lever having line contact with each otheron a line parallel with the diaphragm and at right angles to the lever,in combination with resilient tension members secured to the sound boxand engaging the lever from different directions such as will affordtension stresses cooperating to press the lever bearing downward uponthe box hearing, but mutually opposed and approximately balanced inother directions, and adjustable means for moving said bearings andlever substantially against the downward pressure to increase thelongitudinal tens1on of the resilient tension members and the amount ofsaid down ward pressure Without substantially dis turbing theapproximate balance of their tensions in other directions.

Signed at Buffalo in the county of Erie and State of New York, this 10thday of June, A. D. 1918.

ELWOOD GRISSINGER.

